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Hamilton-Realtime-MDD-20161.Pdf Psychiatry Research: Neuroimaging ∎ (∎∎∎∎) ∎∎∎–∎∎∎ Contents lists available at ScienceDirect Psychiatry Research: Neuroimaging journal homepage: www.elsevier.com/locate/psychresns Effects of salience-network-node neurofeedback training on affective biases in major depressive disorder J. Paul Hamilton a,n, Gary H. Glover b, Epifanio Bagarinao c, Catie Chang d, Sean Mackey c, Matthew D. Sacchet e, Ian H. Gotlib f a Center for Social and Affective Neuroscience, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden b Department of Radiology, Stanford University, Stanford, CA, USA c Department of Anesthesiology, Stanford University, Stanford, CA, USA d Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA e Neurosciences Program, Stanford University, Stanford, CA, USA f Department of Psychology, Stanford University, Stanford, CA, USA article info abstract Article history: Neural models of major depressive disorder (MDD) posit that over-response of components of the brain's Received 19 June 2014 salience network (SN) to negative stimuli plays a crucial role in the pathophysiology of MDD. In the Received in revised form present proof-of-concept study, we tested this formulation directly by examining the affective con- 8 January 2016 sequences of training depressed persons to down-regulate response of SN nodes to negative material. Accepted 14 January 2016 Ten participants in the real neurofeedback group saw, and attempted to learn to down-regulate, activity from an empirically identified node of the SN. Ten other participants engaged in an equivalent procedure Keywords: with the exception that they saw SN-node neurofeedback indices from participants in the real neuro- Major depressive disorder feedback group. Before and after scanning, all participants completed tasks assessing emotional Neurofeedback responses to negative scenes and to negative and positive self-descriptive adjectives. Compared to Functional magnetic resonance imaging participants in the sham-neurofeedback group, from pre- to post-training, participants in the real- Salience network Information processing biases neurofeedback group showed a greater decrease in SN-node response to negative stimuli, a greater decrease in self-reported emotional response to negative scenes, and a greater decrease in self-reported emotional response to negative self-descriptive adjectives. Our findings provide support for a neural formulation in which the SN plays a primary role in contributing to negative cognitive biases in MDD. & 2016 Elsevier Ireland Ltd. All rights reserved. 1. Introduction response to positive relative to neutral stimuli in MDD (Hamilton et al., 2012). Based on these findings, we presented a neural Over the last two decades, neuroimaging investigations of account of the well-documented heightened response to negative Major Depressive Disorder (MDD) have been instrumental in stimuli in MDD, which has been hypothesized to play a significant increasing our understanding of this prevalent and debilitating role in the etiology and maintenance of this disorder (Beck, 1976; condition (Kessler and Wang, 2009). Sufficient data have now Gotlib and Joormann, 2010). In this formulation, we posit that accumulated from functional neuroimaging investigations of through monosynaptic projections to the amygdala, dACC, and depression that, through meta-analytic integration, we have been fronto-insular cortex (Jones and Burton, 1976; Mufson and Mesu- able to identify the neural abnormalities that have been found lam, 1984; Padmala et al., 2010), heightened baseline activity in most reliably to characterize this disorder. Specifically, in a recent the pulvinar nucleus in depression (Hamilton et al., 2012) potentiates response of these primary limbic nodes to affective meta-analysis of studies using task-based functional magnetic information. resonance imaging (FMRI), we found reliably increased response In this model, fronto-insular cortex, dACC, and amygdala — in fronto-insular cortex, amygdala, and dorsal anterior cingulate primary nodes in the brain’s salience network (SN), which is cortex (dACC) to negative stimuli relative to neutral stimuli; postulated to undergird perception of and response to personally importantly, we did not observe this pattern with respect to relevant stimuli (SN; Seeley et al., 2007) — play a crucial role in biasing the processing of negative information in MDD. This and n Corresponding author. similar formulations proposed by clinical neuroscientists (e.g., E-mail address: [email protected] (J.P. Hamilton). Menon, 2011) are difficult to test directly using traditional http://dx.doi.org/10.1016/j.pscychresns.2016.01.016 0925-4927/& 2016 Elsevier Ireland Ltd. All rights reserved. Please cite this article as: Hamilton, J.P., et al., Effects of salience-network-node neurofeedback training on affective biases in major depressive disorder. Psychiatry Research: Neuroimaging (2016), http://dx.doi.org/10.1016/j.pscychresns.2016.01.016i 2 J.P. Hamilton et al. / Psychiatry Research: Neuroimaging ∎ (∎∎∎∎) ∎∎∎–∎∎∎ functional neuroimaging paradigms, which typically identify only 2. Methods and materials neural correlates of cognitive or emotional activity. Given this limitation of traditional FMRI paradigms in making causal attri- 2.1. Participants butions, in the present study we used an FMRI-based neurofeed- Twenty-two adults diagnosed with MDD initially participated in this study. All back system that allows individuals to see and learn to modulate participants met criteria for a DSM-IV diagnosis of MDD based on their responses to regional brain responses. The implementation of this method the Structured Clinical Interview for DSM (SCID; First et al., 2001), administered by permits investigators to examine the effects on behavior of mod- trained diagnostic interviewers. Depressed individuals with a current comorbid ulating neural activation (Weiskopf et al., 2004), as opposed to the diagnosis of any Axis-I disorder other than Social Anxiety Disorder (SAD) were not included in the study. Given that we were comparing two groups of depressed more typical examination of the effects on the brain of manip- participants (real versus sham NFT), we included depressed individuals who were ulating behavior. Such FMRI neurofeedback systems have now taking antidepressant medication in this study because we would not be con- been used successfully to teach healthy individuals to volitionally founding medication status with psychiatric diagnosis and, importantly, because this would bolster the generalizability of our findings to the general population of alter response in sensorimotor (DeCharms et al., 2004), and limbic depressed persons, over half of whom take psychotropic medications (Pratt et al., regions (Caria et al., 2007; Hamilton et al., 2011), and to reduce the 2011). At the end of the interview session, all participants completed the Beck experience of pain (deCharms et al., 2005). Depression Inventory-II (BDI-II; Beck et al., 1979) and the Positive and Negative Recent studies using FMRI neurofeedback in MDD have Affect Schedule (PANAS; Watson et al., 1988). The BDI-II and PANAS are frequently used and well validated self-report measures of the severity of depressive symp- explored the therapeutic utility of this method in depression. A toms and levels of positive and negative affect, respectively. All stages of the re- seminal, non-placebo-controlled study showed that it is possible search presented here were carried out in accordance with The Code of Ethics of to teach depressed persons to increase idiographic neural activity the World Medical Association (Declaration of Helsinki) for experiments involving humans. associated with positive affect and, in doing so, decrease depres- To assess cognitive, behavioral, and neural effects of NFT, we assigned partici- sive symptomatology (Linden et al., 2012). Another recent study pants to one of two groups: REAL, in which participants saw real-time neural showed that teaching depressed persons to increase amygdala response data from a component of their own SN, and SHAM, in which participants saw, in the context of an otherwise equivalent neurofeedback procedure, neural activity during recall of happy autobiographical memories response data from participants in the REAL group instead of their own neural data. increases happiness and decreases anxiety in MDD (Young et al., We elected to use a sham NFT control group—as opposed to a control group seeing 2014). While not controlling for placebo effects, these studies have neurofeedback from a control region not implicated in depression—because this form of experimental control is the only way to ensure that the positive and ne- provided strong preliminary support for the clinical efficacy of gative reinforcement provided from neurofeedback, and the potential effects of this FMRI neurofeedback paradigms. feedback on subsequent task performance, were precisely controlled. Importantly, In the current proof-of-concept study, we take a different per- two researchers were involved in NFT scanning: one who interacted with partici- spective relative to previous, clinically oriented work by using pants and was blind to group assignment and one that ran the NFT interface and who was not blind to group assignment. Further, in keeping with the objective of FMRI neurofeedback as a tool to test and develop neural models of this study
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